Dissociable encoding of motivated behavior by parallel thalamo-striatal projections

The successful pursuit of goals requires the coordinated execution and termination of actions that lead to positive outcomes. This process relies on motivational states that are guided by internal drivers, such as hunger or fear. However, the mechanisms by which the brain tracks motivational states to shape instrumental actions are not fully understood. The paraventricular nucleus of the thalamus (PVT) is a midline thalamic nucleus that shapes motivated behaviors via its projections to the nucleus accumbens (NAc)1,2,3,4,5,6,7,8 and monitors internal state via interoceptive inputs from the hypothalamus and brainstem.3,9,10,11,12,13,14 Recent studies indicate that the PVT can be subdivided into two major neuronal subpopulations, namely PVTD2(+) and PVTD2(-), which differ in genetic identity, functionality, and anatomical connectivity to other brain regions, including the NAc.4,15,16 In this study, we used fiber photometry to investigate the in vivo dynamics of these two distinct PVT neuronal types in mice performing a foraging-like behavioral task. We discovered that PVTD2(+) and PVTD2(-) neurons encode the execution and termination of goal-oriented actions, respectively. Furthermore, activity in the PVTD2(+) neuronal population mirrored motivation parameters such as vigor and satiety. Similarly, PVTD2(-) neurons also mirrored some of these parameters, but to a much lesser extent. Importantly, these features were largely preserved when activity in PVT projections to the NAc was selectively assessed. Collectively, our results highlight the existence of two parallel thalamo-striatal projections that participate in the dynamic regulation of goal pursuits and provide insight into the mechanisms by which the brain tracks motivational states to shape instrumental actions.

Factors influencing operationalization of Integrated Disease Surveillance in Malawi

OBJECTIVES

Malawi's disease surveillance system is built on several different data sources and systems and is informed by the Integrated Diseases Surveillance and Response (IDSR) strategy. This study was carried out as part of a larger multicountry study to identify context-specific factors, which influence the operationalization of integrated disease surveillance.

STUDY DESIGN AND METHODS

A total of six focus group discussions were conducted with 43 relevant personnel at the primary and secondary healthcare levels in two districts (Lilongwe and Dowa) and at the national level. The discussions were analyzed and sorted into predefined categories based on the domains of the International Association of Public Health conceptual framework.

RESULTS

We found ongoing efforts to enhance integrated disease surveillance operationalization, including the establishment of the Public Health Institute of Malawi for coordination, digitalizing the surveillance system through One Health Surveillance Platform, and improving communication among rapid response teams using WhatsApp. The adoption of World Health Organization's third edition IDSR technical guidelines was also underway. Nonetheless, there were major implementation barriers such as parallel and uncoordinated surveillance systems, priority conditions that cannot be diagnosed at the point of reporting, lack of case definitions and diagnostic codes for priority conditions, reporting forms with unexplained acronyms, illegible data sources, unstable electronic data transfers, inadequate supervision and training, poor enforcement of reporting from private health facilities, high reporting burden, and lack of and feedback to those reporting.

CONCLUSIONS

The results fit well into the predefined categories used. The study reveals basic problems with the operationalization, tools, and reporting forms used for IDSR. These findings may have implications for practice and policy in Malawi and other countries where IDSR is the national strategy for surveillance.

Dissociable encoding of motivated behavior by parallel thalamo-striatal projections

The successful pursuit of goals requires the coordinated execution and termination of actions that lead to positive outcomes. This process is thought to rely on motivational states that are guided by internal drivers, such as hunger or fear. However, the mechanisms by which the brain tracks motivational states to shape instrumental actions are not fully understood. The paraventricular nucleus of the thalamus (PVT) is a midline thalamic nucleus that shapes motivated behaviors via its projections to the nucleus accumbens (NAc)1-8 and monitors internal state via interoceptive inputs from the hypothalamus and brainstem3,9-14. Recent studies indicate that the PVT can be subdivided into two major neuronal subpopulations, namely PVTD2(+) and PVTD2(-), which differ in genetic identity, functionality, and anatomical connectivity to other brain regions, including the NAc4,15,16. In this study, we used fiber photometry to investigate the in vivo dynamics of these two distinct PVT neuronal types in mice performing a reward foraging-like behavioral task. We discovered that PVTD2(+) and PVTD2(-) neurons encode the execution and termination of goal-oriented actions, respectively. Furthermore, activity in the PVTD2(+) neuronal population mirrored motivation parameters such as vigor and satiety. Similarly, PVTD2(-) neurons, also mirrored some of these parameters but to a much lesser extent. Importantly, these features were largely preserved when activity in PVT projections to the NAc was selectively assessed. Collectively, our results highlight the existence of two parallel thalamo-striatal projections that participate in the dynamic regulation of goal pursuits and provide insight into the mechanisms by which the brain tracks motivational states to shape instrumental actions.

Measurement of SARS-CoV-2 in air and on surfaces in Scottish hospitals

BACKGROUND

There are still uncertainties in our knowledge of the amount of SARS-CoV-2 virus present in the environment - where it can be found, and potential exposure determinants - limiting our ability to effectively model and compare interventions for risk management.

AIM

This study measured SARS-CoV-2 in three hospitals in Scotland on surfaces and in air, alongside ventilation and patient care activities.

METHODS

Air sampling at 200 L/min for 20 min and surface sampling were performed in two wards designated to treat COVID-19-positive patients and two non-COVID-19 wards across three hospitals in November and December 2020.

FINDINGS

Detectable samples of SARS-CoV-2 were found in COVID-19 treatment wards but not in non-COVID-19 wards. Most samples were below assay detection limits, but maximum concentrations reached 1.7×10³ genomic copies/m³ in air and 1.9×10⁴ copies per surface swab (3.2×10² copies/cm² for surface loading). The estimated geometric mean air concentration (geometric standard deviation) across all hospitals was 0.41 (71) genomic copies/m³ and the corresponding values for surface contamination were 2.9 (29) copies/swab. SARS-CoV-2 RNA was found in non-patient areas (patient/visitor waiting rooms and personal protective equipment changing areas) associated with COVID-19 treatment wards.

CONCLUSION

Non-patient areas of the hospital may pose risks for infection transmission and further attention should be paid to these areas. Standardization of sampling methods will improve understanding of levels of environmental contamination. The pandemic has demonstrated a need to review and act upon the challenges of older hospital buildings meeting current ventilation guidance.

Randomized in situ clinical trial evaluating erosion protection efficacy of a 0.454% stannous fluoride dentifrice

OBJECTIVES

To assess the protective effects of a 0.454% stabilized stannous fluoride dentifrice and a marketed triclosan dentifrice against enamel erosion in a 10-day in situ model.

METHODS

This was a double-blind, randomized, 2-treatment, 4-period, crossover in situ trial involving healthy adult participants. Participants were randomized to a treatment sequence involving the following products: a highly bioavailable 0.454% stannous fluoride dentifrice (Procter & Gamble) and a marketed dentifrice control containing 0.24% sodium fluoride and 0.3% triclosan (Colgate-Palmolive). Each study period took place over 10 days. Participants wore an intra-oral appliance retaining two polished human enamel samples for 6 hours per day. Two times per day they swished with the assigned dentifrice slurry and four times per day they swished with 250 mL of orange juice (25 mL per minute) over a 10-minute period. Contact profilometry measurements were made for each sample at baseline and day 10 to determine surface change.

RESULTS

Thirty-six participants were enrolled and 33 completed the study (mean age = 40.5 years). The stannous fluoride dentifrice demonstrated 93.5% less enamel loss than the NaF/triclosan dentifrice (P < 0.001) at Day 10, with median enamel loss of 0.097 µm and 1.495 µm, respectively. Both products were well tolerated.

CONCLUSION

The stannous fluoride dentifrice demonstrated significantly greater erosion protection efficacy relative to the NaF/triclosan dentifrice in this randomized in situ clinical trial.

Observation of Medium-Induced Modifications of Jet Fragmentation in Pb-Pb Collisions at sqrt[s_{NN}]=5.02 TeV Using Isolated Photon-Tagged Jets

Measurements of fragmentation functions for jets associated with an isolated photon are presented for the first time in pp and Pb-Pb collisions. The analysis uses data collected with the CMS detector at the CERN LHC at a nucleon-nucleon center-of-mass energy of 5.02 TeV. Fragmentation functions are obtained for jets with p_{T}^{jet}>30  GeV/c in events containing an isolated photon with p_{T}^{γ}>60  GeV/c, using charged tracks with transverse momentum p_{T}^{trk}>1  GeV/c in a cone around the jet axis. The association with an isolated photon constrains the initial p_{T} and azimuthal angle of the parton whose shower produced the jet. For central Pb-Pb collisions, modifications of the jet fragmentation functions are observed when compared to those measured in pp collisions, while no significant differences are found in the 50% most peripheral collisions. Jets in central Pb-Pb events show an excess (depletion) of low (high) p_{T} particles, with a transition around 3  GeV/c. This measurement shows for the first time the in-medium shower modifications of partons (quark dominated) with well-defined initial kinematics. It constitutes a new well-controlled reference for testing theoretical models of the parton passage through the quark-gluon plasma.

Search for third-generation scalar leptoquarks decaying to a top quark and a τ lepton at s = 13 Te

A search for pair production of heavy scalar leptoquarks (LQs), each decaying into a top quark and a τ lepton, is presented. The search considers final states with an electron or a muon, one or two τ leptons that decayed to hadrons, and additional jets. The data were collected in 2016 in proton-proton collisions ats = 13 Te with the CMS detector at the LHC, and correspond to an integrated luminosity of 35.9fb - 1 . No evidence for pair production of LQs is found. Assuming a branching fraction of unity for the decay LQ → t τ , upper limits on the production cross section are set as a function of LQ mass, excluding masses below 900Ge at 95% confidence level. These results provide the most stringent limits to date on the production of scalar LQs that decay to a top quark and a τ lepton.

Search for Physics Beyond the Standard Model in Events with High-Momentum Higgs Bosons and Missing Transverse Momentum in Proton-Proton Collisions at 13 TeV

A search for physics beyond the standard model in events with one or more high-momentum Higgs bosons, H, decaying to pairs of b quarks in association with missing transverse momentum is presented. The data, corresponding to an integrated luminosity of 35.9  fb^{-1}, were collected with the CMS detector at the LHC in proton-proton collisions at the center-of-mass energy sqrt[s]=13  TeV. The analysis utilizes a new b quark tagging technique based on jet substructure to identify jets from H→bb[over ¯]. Events are categorized by the multiplicity of H-tagged jets, jet mass, and the missing transverse momentum. No significant deviation from standard model expectations is observed. In the context of supersymmetry (SUSY), limits on the cross sections of pair-produced gluinos are set, assuming that gluinos decay to quark pairs, H (or Z), and the lightest SUSY particle, LSP, through an intermediate next-to-lightest SUSY particle, NLSP. With large mass splitting between the NLSP and LSP, and 100% NLSP branching fraction to H, the lower limit on the gluino mass is found to be 2010 GeV.

Search for Heavy Neutral Leptons in Events with Three Charged Leptons in Proton-Proton Collisions at sqrt[s]=13 TeV

A search for a heavy neutral lepton N of Majorana nature decaying into a W boson and a charged lepton is performed using the CMS detector at the LHC. The targeted signature consists of three prompt charged leptons in any flavor combination of electrons and muons. The data were collected in proton-proton collisions at a center-of-mass energy of 13 TeV, with an integrated luminosity of 35.9  fb^{-1}. The search is performed in the N mass range between 1 GeV and 1.2 TeV. The data are found to be consistent with the expected standard model background. Upper limits are set on the values of |V_{eN}|^{2} and |V_{μN}|^{2}, where V_{ℓN} is the matrix element describing the mixing of N with the standard model neutrino of flavor ℓ. These are the first direct limits for N masses above 500 GeV and the first limits obtained at a hadron collider for N masses below 40 GeV.

Erosion protection efficacy of a 0.454% stannous fluoride dentifrice versus an arginine-containing dentifrice

PURPOSE

To assess the anti-erosion effects of a 0.454% stannous fluoride dentifrice versus a marketed dentifrice in an in situ clinical study.

METHODS

This was a double-blind, randomized and controlled, two-treatment, four-period crossover clinical study involving healthy adults. Each study period was 10 days. Subjects were randomized to one of two dentifrice products each period: an experimental 0.454% stannous fluoride dentifrice (1,100 ppm fluoride) or a marketed 1.5% arginine-containing dentifrice (Colgate Maximum Cavity Protection, 1,450 ppm fluoride). Subjects wore an intra-oral appliance fitted with two polished human enamel samples for 6 hours per day, swishing with the assigned dentifrice slurry twice a day in addition to sipping and swishing with 250 ml of orange juice for 10 minutes (in increments of 25 ml each minute) four times each day. Contact profilometry was used to measure surface loss of tooth enamel over the course of the study. Two measurements for each sample were taken at baseline and Day 10.

RESULTS

35 subjects were randomized to treatment and 31 completed the study (mean age = 40 years). At Day 10, enamel loss means were 0.128 µm for the stannous fluoride dentifrice and 1.377 µm for the arginine-containing dentifrice, respectively (P< 0.001). This represents 90.7% less enamel loss for the stannous fluoride dentifrice. Both products were well tolerated.

CLINICAL SIGNIFICANCE

The 0.454% stannous fluoride dentifrice demonstrated significantly greater protection to human enamel against erosive acid challenges relative to the marketed 1.5% arginine-containing dentifrice in this in situ clinical study.

A randomised clinical study to measure the anti-erosion benefits of a stannous-containing sodium fluoride dentifrice

Background:

To compare the enamel protection efficacy of stannous-containing sodium fluoride and sodium monofluorophosphate (MFP)/triclosan dentifrices marketed in India in an in situ erosion model with acidic challenge.

Materials and Methods:

This randomised and controlled, in situ, supervised, double-blind clinical trial employed a two-treatment, four-period crossover design, wherein subjects wore an appliance fitted with human enamel samples 6 h/day during each 10 day treatment period and swished twice daily with their assigned dentifrice slurry: Oral-B^® Pro-Health (maximum 1,000 ppm F as sodium fluoride with stannous chloride) or Colgate^® Strong Teeth with Cavity Protection (maximum 1,000 F as sodium MFP and triclosan). Subjects swished with 250 ml of orange juice over a 10 min period after each treatment and twice daily for the acidic erosive challenge. Enamel samples were measured for tooth surface loss using contact profilometry at baseline and day 10.

Results:

A total of 34 subjects were randomised to treatment; 32 subjects completed the final visit. Baseline profilometry measurements of the specimen surfaces were near zero within ± 0.3 μm, and no statistically significant difference (P > 0.48) on average was observed between the two test dentifrices. At day 10, the stannous-containing dentifrice demonstrated 88% less erosion (P < 0.0001) relative to the MFP/triclosan dentifrice. Estimated medians (95% confidence intervals) were 0.21 μm (0.17, 0.25) for the stannous-containing dentifrice versus 1.66 μm (1.39, 1.99) for the MFP/triclosan dentifrice. Both dentifrices were well-tolerated.

Conclusions:

Compared with MFP/triclosan toothpaste, a stabilised stannous-containing sodium fluoride dentifrice gave statistically significantly greater protection against tooth enamel surface loss in situ following repeated acid erosive challenge.

Normal values for transbulbar sonography and magnetic resonance imaging of the optic nerve sheath diameter (ONSD) in children and adolescents

PURPOSE

To establish normal values of the optic nerve sheath diameter (ONSD) in children and adolescents for transbulbar sonography and magnetic resonance imaging.

MATERIALS AND METHODS

In 99 children and adolescents (age: 5.6 - 18.6 years, mean: 12 years) without neurologic or ophthalmologic disease, measurements of the ONSD with transbulbar sonography were performed. For comparison 59 children and adolescents (age: 5.1 - 17.4 years, mean 12.3 years) with a normal MR examination of the brain had measurements of the ONSD on a T2-weighted thin section sequence of the orbit. Besides establishing modality-related normal values, age dependency, accuracy and reproducibility of measurements were assessed.

RESULTS

Overall the mean ONSD was 5.75 ± 0.52 mm for transbulbar sonography and 5.69 ± 0.31 mm for MRI. There was no statistical significance between the 95 % percentiles and age for both transbulbar sonography (p = 0.332) and MRI (p = 0.336). As a parameter for the reproducibility of measurements, the repeatability coefficient (RC) was between 0.34 mm and 0.46 mm. The concordance correlation coefficient (CCC) values revealed a high agreement between readers both for transbulbar sonography (0.868) and MRI (0.796).

CONCLUSION

Normal values for ONSD in children and adolescents found in this study are significantly higher than assumed. The values found for transbulbar sonography are confirmed by comparable results for MR measurements. A precise sonographic measurement technique and the consideration of normal values found hereby are essential for correct interpretation of ONSD measurements in children and adolescents.

A randomised in situ trial, measuring the anti-erosive properties of a stannous-containing sodium fluoride dentifrice compared with a sodium fluoride/potassium nitrate dentifrice

OBJECTIVES

To determine if a stabilised, stannous-containing sodium fluoride dentifrice provides greater enamel protection in situ against intraoral dietary erosive challenges compared with a sodium fluoride/potassium nitrate dentifrice.

METHODS

A single-centre, investigator blind, randomised, supervised, two-treatment, non-brushing, four-period crossover in situ study was undertaken, with each test period being 15 days. Thirty-five healthy adult subjects were recruited to participate in the study, which included four erosive acid challenges per day. Subjects were randomised to product treatment, which included either: (1) a stannous-containing sodium fluoride dentifrice (Oral-B(®) Pro-Expert Sensitive) or (2) a sodium fluoride/potassium nitrate dentifrice (Sensodyne(®) Pronamel(®) ). Each study subject wore an intraoral appliance retaining two sterilised, polished human enamel samples for 6 hours/day. Subjects swished with an allocated dentifrice slurry twice a day and with 250 ml of orange juice for 10 minutes (25 ml/minute over a 10-minute period) four times per day. The primary and secondary outcomes for this study were enamel loss measured using contact profilometry at days 15 and 5, respectively, using parametric analysis methods.

RESULTS

At day 15, a 38% lower enamel loss (P < 0.0001) was observed, with estimated medians of 2.03 μm (SE 0.247) and 3.30 μm (SE 0.379), in favour of the stannous-containing dentifrice. At day 5, specimens treated with the stannous-containing sodium fluoride dentifrice demonstrated 25% less enamel loss than those treated with the sodium fluoride/potassium nitrate dentifrice. Treatment differences at day 5 were also statistically significant (P < 0.05), with estimated medians of 1.37 μm (SE 0.177) and 1.83 μm (SE 0.223), respectively.

CONCLUSIONS

Results of this in situ study suggest the stabilised, stannous-containing sodium fluoride dentifrice could be used to provide significantly greater protection to enamel from erosive acid challenge compared with that provided by conventional fluoride-containing products.

Constraints on cosmic strings from the LIGO-Virgo gravitational-wave detectors

Cosmic strings can give rise to a large variety of interesting astrophysical phenomena. Among them, powerful bursts of gravitational waves (GWs) produced by cusps are a promising observational signature. In this Letter we present a search for GWs from cosmic string cusps in data collected by the LIGO and Virgo gravitational wave detectors between 2005 and 2010, with over 625 days of live time. We find no evidence of GW signals from cosmic strings. From this result, we derive new constraints on cosmic string parameters, which complement and improve existing limits from previous searches for a stochastic background of GWs from cosmic microwave background measurements and pulsar timing data. In particular, if the size of loops is given by the gravitational backreaction scale, we place upper limits on the string tension Gμ below 10(-8) in some regions of the cosmic string parameter space.

Measurement of the Optic Nerve Sheath Diameter in Children: Comparison Between Transbulbar Sonography and Magnetic Resonance Imaging

PURPOSE

 To evaluate the accuracy of measurements of the optic nerve sheath diameter (ONSD) in children by comparing transbulbar sonography with magnetic resonance imaging (MRI).

MATERIALS AND METHODS

 65 children (age: 3 mo- 17y; mean age: 11.3y) underwent MR imaging of the brain including a heavily T 2-w sequence of the orbit and transbulbar sonography using a 17 MHz linear array transducer. Measurements of the ONSD were performed retrospectively by two experienced readers and all images were evaluated regarding the image quality. Bland-Altman Plots were produced to assess the accuracy of measurements. The correlation between readers and between MR imaging and transbulbar sonography was calculated by the concordance correlation coefficient (CCC).

RESULTS

 Overall the mean values of the ONSD for MRI (5.86 ± 0.66 mm) and transbulbar sonography (5.86 ± 0.71 mm) were identical. There was a high correlation between readers for measurements of the ONSD both for transbulbar sonography (CCC = 0.93) as well as for MRI (CCC = 0.9). Comparing the measurement values between transbulbar sonography and MRI, the correlation of ONSD values was good to moderate with a high dependency on image quality (CCC [0.31, 0.68]).

CONCLUSION

 We were able to demonstrate that the ONSD values of transbulbar sonography in children correlate well with MRI if the relevant anatomic structures are depicted and the measuring points are set correctly. Based on the findings of our study, it seems necessary to define normal and cut-off values for the ONSD in children again to finally assess the clinical relevance of the ONSD as a noninvasive parameter for the evaluation of intracranial pressure.

Pilot study of random finger prick glucose testing as a screening tool for type 2 diabetes mellitus in the emergency department

BACKGROUND

A study was undertaken to determine the prevalence of undiagnosed hyperglycaemia among patients in the emergency department (ED) and to evaluate the usefulness of random fingerprick plasma glucose (RFPG) screening in the ED with GP follow-up.

METHODS

A cross-sectional pilot study of 101 non-diabetic patients in the ED aged > or =45 years was performed.

RESULTS

31 (30.7%) had never had diabetic screening. 67 (66.3%) had plasma glucose levels > or =5.5 mmol/l and were advised to consult their GP; 38 (56.7%) did so and 23 (60.5%) of these had follow-up testing. Nine patients (8.9%) were ultimately diagnosed with impaired glucose metabolism.

CONCLUSION

There is considerable potential for diabetic screening in the ED setting.

A randomised controlled trial of intramuscular vs. intravenous antivenom for latrodectism--the RAVE study

BACKGROUND

Widow spider-bite causes latrodectism and is associated with significant morbidity worldwide. Antivenom is given by both the intravenous (IV) and intramuscular (IM) routes and it is unclear which is more effective.

AIM

To compare the effectiveness of IV vs. IM redback spider antivenom.

DESIGN

Randomized controlled trial.

METHODS

Patients with latrodectism were given either IV or IM antivenom according to a randomized double-dummy, double-blind protocol. The first antivenom treatment was followed by another identical treatment after two hours if required. The primary outcome was a clinically significant reduction in pain two hours after the last treatment. A fully Bayesian analysis was used to estimate the probability of the desired treatment effect, predetermined as an absolute difference of 20%.

RESULTS

We randomly allocated 126 patients to receive antivenom IV (64) and IM (62). After antivenom treatment pain improved in 40/64(62%) in the IV group vs. 33/62(53%) in the IM group (+9%; 95% Credible Interval [CrI]: -8% to +26%). The probability of a difference greater than zero (IV superior) was 85% but the probability of a difference >20% was only 10%. In 55 patients with systemic effects, these improved in 58% after IV antivenom vs. 65% after IM antivenom (-8%; 95% CrI: -32% to +17%). Twenty-four hours after antivenom pain had improved in 84% in the IV group vs. 71% in the IM group (+13%; 95% CrI: -2% to +27%). A meta-analysis including data from a previous trial found no difference in the primary outcome between IV and IM administration.

DISCUSSION

The difference between IV and IM routes of administration of widow spider antivenom is, at best, small and does not justify routinely choosing one route over the other. Furthermore, antivenom may provide no benefit over placebo.

[Sonographic detection of normal appendix in children and adolescents]

PURPOSE

The frequency of depiction of the normal appendix by real time B-mode sonography in children was evaluated in a prospective study.

MATERIALS AND METHODS

In 274 consecutive patients, age one to nineteen, without abdominal pain, depiction of the normal appendix was attempted using a 5-12 MHz linear array transducer. The ultrasound examination was performed using the graded compression technique according to the description of Puylaert. Depiction of the normal appendix was graded as a) complete, b) partial and c) unable to be depicted. In addition the position and diameter of the appendix, the examination time and the image quality were documented.

RESULTS

The appendix was depicted completely in 74% of all patients and partially in 10%. In the age group of one to nine years, complete depiction was possible in 86% of the cases. The most common position with 87% was caudal and mediocaudal, 11% of the appendices were located retrocecal and 2% had a cranioventral position. The mean diameter of the appendices was 4.1 mm (range 3-7 mm). The mean examination time to depict the normal appendix completely was 3.7 min compared to 7.6 min in partial or incompletely depicted cases. In most cases in which complete depiction of the appendix was possible, the image quality was excellent.

CONCLUSION

Since the normal appendix in children can be reliably depicted by experienced examiners using high-resolution linear transducers, ultrasound is suitable as a reliable imaging modality for excluding acute appendicitis in children.

A systematic review of the factors which predict return to work for people suffering episodes of poor mental health

INTRODUCTION

Poor mental health is responsible for a large percentage of long term work absence, and only 50% of those who are off work for 6 months or more return to work.

METHOD

We aimed to describe the factors which predict or restrict return to work for people suffering episodes of poor mental health. A literature review was conducted to identify all papers relating to long term mental illness absence.

RESULTS

Fourteen papers of varying methodological quality considered mental health in relation to psychiatric morbidity, depression, stress, and body weight. Successful return to work is predicted by factors related to work, family history, health risk behaviours, social status, and medical condition.

CONCLUSIONS

This study identifies a range of factors which are important in preventing return to work for people with mental health conditions. The factors affecting RTW after a period of sickness absence due to poor mental health are wide ranging and in some cases studies have produced opposing results (particularly in the case of demographic factors). Further research is required to describe the factors which delay return to work for people experiencing episodes of poor mental health.

Anxiety, obsessions and morbid preoccupations in pregnancy and the puerperium

129 mothers referred to specialist psychiatric services in Birmingham and Christchurch were interviewed with the Birmingham Interview. Anxiety disorders were more frequent than depression during pregnancy, and equally frequent after delivery. The focus of pre- and post-partum anxiety may be important for psychological treatment. At a severe level, the most common prepartum theme was fear of foetal death; this was associated with a history of reproductive losses or infertility. After delivery the commonest themes were the pathological fear of cot death and fear of the criticism of mothering skills (which was a clue to a disordered mother-infant relationship). Clinicians should be vigilant for obsessional disorders, querulant (complaining) disorders, post-traumatic stress disorder, conjugal jealousy and dysmorphophobic states, which are all quite common. Patients with "postpartum depression" usually had at least one other (co-morbid) disorder, and 27% had two or more. These findings emphasize the diversity of postpartum psychiatric illness.

The brain 5HTergic response to an acute sound stress in rats with generalized (absence and audiogenic) epilepsy

The brain serotoninergic (5HTergic) system of epileptic subjects can influence their vulnerability to stress. We studied the putative dependency of 5HT neurotransmission parameters on emotional stress, and the presence, types and severity of seizures using rats with genetic generalized (absence and/or audiogenic) epilepsy, of WAG/Rij and Wistar strains. The animals were stressed by exposure to a short aversive noise or left without sound stimulation. Tissue concentrations of 5HT, tryptophan (TRT) and 5-hydroxyindolacetic acid (5HIAA) were assessed by HPLC. The stressor activated the 5HTergic system within thalamus (5HIAA elevated), frontal cortex (5HT, TRT elevated), hypothalamus (increased TRT) in all rats. However, the normal (non-epileptic) rats displayed the highest response in the frontal cortex and the lowest one in the thalamus, as compared to the epileptic rats. Absence-epileptic rats exhibited higher thalamic 5HIAA increase than their controls. Significant correlations existed between propensity of absence epilepsy and 5HTergic parameters measured in the cortex and hypothalamus of absence-epileptic rats. No major difference was found between groups with and without audiogenic epilepsy. The results imply that the stress response depends on the presence of epileptic pathology and the seizure type and severity. The brain 5HT may be involved in the control of the paroxysms and behaviour in absence-epileptic subjects.

A study in vitro of the combined effects of soft drinks and tooth brushing with fluoride toothpaste on the wear of dentine

The aim of this study was to measure loss of dentine produced by soft drinks alone and combined with tooth brushing with and without toothpastes. Groups of flat human dentine specimens were exposed for 10 min and then 30 min to orange juice (OJ), carbonated cola (CC) or modified blackcurrant (MB) drinks alone or after the exposures brushed with a fluoride toothpaste for 10 s. Further groups were exposed to OJ as before but brushed with water or non-fluoride toothpaste or placed in slurries of fluoride paste. Five cycles of each regimen were carried out. Tissue loss was determined by profilometry. Water immersion/brushing and brushing controls were included. OJ and CC produced similar erosion and significantly more than MB. Compared with drinks alone, dentine loss was reduced by fluoride toothpaste brushing but increased by water and non-fluoride toothpaste brushing. Fluoride toothpaste slurry had no significant effect on soft drink erosion. Very little abrasion with brushing alone was recorded over the time frame of these experiments. It is concluded that fluoride toothpaste could provide protection, albeit small, against erosion. The data again support the concept of brushing before meals.

The bleaching depth of a 35% hydrogen peroxide based in-office product: a study in vitro

OBJECTIVES

The aim of the present study was to quantify the penetration of 35% hydrogen peroxide into enamel and dentine and to relate this to the resultant shade change of the tooth.

METHOD

The crowns of 24 caries and developmental defect free human maxillary incisors were stained internally with a standardised tea solution. Twelve specimens were power bleached with light activated 35% hydrogen peroxide and 12 placed in water; both exposure times were 30min. Three different shade assessment methods (Vita shade guide [SG], shade vision system [SVS] and a chromometer) were employed prior to, after tea staining and after power bleaching/water treatments. Twelve specimens each from the bleach group and the water control water group were sectioned mesio-distally. An additional 12 specimens from the bleach and the control group were sectioned labio-palatally. The stain area for each specimen was measured using image analysis software.

RESULTS

With tea staining, the mean changes in Vita shade guide units (SGU) ranged from 3.66 to 8.33. With the SVS system changes of 3.66-9 units were seen. Chromometer readings showed that following bleaching the L* values moved in the direction of black (3.8-6.7) and a* and b* values were in the red (0.3) and yellow (1.5) direction, respectively. Samples bleached and sectioned mesio-distally showed stain coverage of 28.6-39.4%, while palatal sections showed stain coverage of 58-72%. Control samples, whether sectioned mesio-distally or labio-palatally, showed staining throughout the dentine (97-100% coverage).

CONCLUSION

A 35% hydrogen peroxide in-office bleaching gel demonstrated bleaching into dentine of uniform depth.

A safety study in vitro for the effects of an in-office bleaching system on the integrity of enamel and dentine

OBJECTIVE

The aim of this study was to investigate safety concerns with bleaching procedures by studying the effects of a high concentration hydrogen peroxide (HP) in-surgery bleaching product on enamel and dentine.

METHOD

Flat enamel and dentine samples embedded in epoxy resin were prepared from human third molar teeth. Erosion of enamel: groups of enamel samples were treated with 35% HP then citric acid (CA) or brushing with toothpaste or CA alone and water alone. Enamel Loss was measured using a profilometer. Abrasion/erosion of dentine: groups of dentine specimens were treated as follows: Group 1--brushed with water for 30 min. Group 2--brushed with 35% HP for 30 min. Group 3--power bleached for 30 min and then Group 4--brushed with toothpaste for 1 minute. Group 5--water soaked for 30 min followed by brushing with toothpaste for 1 min. Group 6--orange juice soaked for 30 min followed by brushing with toothpaste for 1 min. Treatment effects were measured using a profilometer. Hardness tests: enamel and dentine specimens were hardness tested using a Wallace indenter prior to and post bleaching. Scanning Electron Microscopy: enamel and dentine specimens were taped and the exposed tissue treated with 35% HP and then studied under scanning electronmicroscopy (SEM).

RESULTS

Enamel erosion: bleaching enamel samples had no measurable effect on enamel. Pre-bleaching had no significant effect on subsequent CA erosion or brushing. Abrasion/erosion of dentine: no significant differences were found between treatments 1-5 with little change from baseline detected. Orange juice (Group 6) produced considerable and significantly more erosion than other treatments. Hardness tests: there were no significant changes in hardness values for enamel and dentine. SEM: there was no evidence of any topographical changes to either enamel or dentine.

CONCLUSION

Using one of the highest concentrations of HP for tooth bleaching procedures and maximum likely peroxide exposure, there was no evidence of deleterious effects on enamel or dentine. It must be assumed that studies which reported adverse effects on enamel and or dentine of bleaches reflect not the bleach itself but the pH of the formulation used.

The assessment of poorly performing doctors: the development of the assessment programmes for the General Medical Council's Performance Procedures

BACKGROUND

Modernization of medical regulation has included the introduction of the Professional Performance Procedures by the UK General Medical Council in 1995. The Council now has the power to assess any registered practitioner whose performance may be seriously deficient, thus calling registration (licensure) into question. Problems arising from ill health or conduct are dealt with under separate programmes.

METHODS

This paper describes the development of the assessment programmes within the overall policy framework determined by the Council. Peer review of performance in the workplace (Phase 1) is followed by tests of competence (Phase 2) to reflect the relationship between clinical competence and performance. The theoretical and research basis for the approach are presented, and the relationship between the qualitative methods in Phase 1 and the quantitative methods in Phase 2 explored.

CONCLUSIONS

The approach is feasible, has been implemented and has stood legal challenge. The assessors judge and report all the evidence they collect and may not select from it. All their judgements are included and the voice of the lay assessor is preserved. Taken together, the output from both phases forms an important basis for remediation and training should it be required.

The General Medical Council's Performance Procedures: peer review of performance in the workplace

The General Medical Council procedures to assess the performance of doctors who may be seriously deficient include peer review of the doctor's practice at the workplace and tests of competence and skills. Peer reviews are conducted by three trained assessors, two from the same speciality as the doctor being assessed, with one lay assessor. The doctor completes a portfolio to describe his/her training, experience, the circumstances of practice and self rate his/her competence and familiarity in dealing with the common problems of his/her own discipline. The assessment includes a review of the doctor's medical records; discussion of cases selected from these records; observation of consultations for clinicians, or of relevant activities in non-clinicians; a tour of the doctor's workplace; interviews with at least 12 third parties (five nominated by the doctor); and structured interviews with the doctor. The content and structure of the peer review are designed to assess the doctor against the standards defined in Good Medical Practice, as applied to the doctor's speciality. The assessment methods are based on validated instruments and gather 700-1000 judgements on each doctor. Early experience of the peer review visits has confirmed their feasibility and effectiveness.

Developmental changes in nicotinic receptor mRNAs and responses to nicotine in the suprachiasmatic nucleus and other brain regions

Our previous studies demonstrated that nicotine induces c-fos expression in the suprachiasmatic nucleus (SCN) of the rat during a narrow developmental window occurring in the perinatal period. We have extended these observations by showing that c-fos cannot be induced in the adult SCN by nicotine even during the subjective night, when phase shifts do occur. In contrast to the SCN, significant induction of c-fos and NGFI-A was observed in the medial habenula and paraventricular nucleus at all circadian times. In the fetal rat SCN we show that NGFI-A and junB are also induced by nicotine, but not c-jun. To investigate whether changes in nicotinic acetylcholine receptor (nAChR) expression in the SCN may underlie this change in sensitivity during the perinatal period, we examined nAChR mRNAs across this developmental period. By Northern analyses, alpha2, alpha3 and alpha4 subunit mRNAs are relatively abundant in the fetal SCN but decline substantially in the adult. alpha7 mRNA increases substantially while beta2 mRNA is relatively abundant throughout development. We also examine expression in the whole mouse brain beginning at embryonic day 11. Many mRNA sizes for nAChR subunits in both the rat and mouse are characterized here for the first time by Northern analyses and some show very large changes in expression across development. In particular, a small 1.4 kb alpha2-related mRNA is highly expressed during early development, perhaps indicating an important novel function for this subunit.

Sevoflurane anesthesia in desert tortoises (Gopherus agassizii)

The effects of sevoflurane on anesthesia induction, recovery, ventricular pressures, heart rate, ventricular pH, blood gas values, and electrolytes were evaluated in desert tortoises (Gopherus agassizii). Tortoises were orotracheally intubated while awake and ventilated manually with 3-7% sevoflurane in oxygen (1 L/min) to achieve desired expired sevoflurane concentrations. Data, consisting of induction time, recovery time, systolic, diastolic, and mean ventricular pressures, heart rate, ventricular pH, blood gas values, and electrolytes, were collected prior to anesthesia and sequentially at 2.50% and 3.75% expired sevoflurane as measured at the junction of the endotracheal tube and the breathing circuit. Blood pressure was measured and blood samples were collected through a 25-ga needle passed through a cardiac access port that was placed while the tortoises were in dorsal recumbency. Mean (+/-SE) induction time was 2.55+/-0.55 min, recovery time was 27.58+/-7.55 min, and duration of anesthesia was 105+/-12 min. Mean (+/-SD) values for systolic, diastolic, and mean ventricular pressures in awake tortoises were 28+/-3 mm Hg, 22+/-2 mm Hg, and 24+/-2 mm Hg, respectively. Sevoflurane (2.5% expired) significantly decreased systolic (14+/-3 mm Hg), diastolic (12+/-1 mm Hg), and mean (13+/-1 mm Hg) ventricular pressures compared with those of awake tortoises. Ventricular pressures did not decrease further with increasing depth of anesthesia. Heart rate (32+/-4 beats/min) did not change significantly under sevoflurane anesthesia. Sevoflurane administration increased ventricular PO2 but did not change Na+, K+, or iCa++ concentrations. Sevoflurane appears to provide safe and effective anesthesia with rapid induction and recovery.

Radiotelemetrically recorded blood pressure and heart rate changes in relation to plasma catecholamine levels during parturition in the conscious, unrestrained goat

The aim of this study was to investigate the extent of sympathetic nervous system activation during parturition in four unrestrained goats. Chronically implanted radiotelemetry devices registered heart rate and arterial blood pressure around the clock and blood was sampled for determination of plasma adrenaline and noradrenaline concentrations before, during and after labour. Two goats delivered two kids after moderately intensive abdominal contractions. A third goat had dystocia, and was treated with prostaglandin F2 alpha. One normal kid and one mummified foetus were delivered manually. After milking, a third kid was born spontaneously. The fourth goat experienced severe abdominal contractions and delivered one kid. Mean blood pressure was 69 +/- 2 mmHg the day before parturition, increased gradually during the labour pains, and reached a maximal value of 120 +/- 7 mmHg when the head of the first kid was visible (P < or = 0.05). Heart rate was 134 +/- 4 beats min-1 the day before parturition and peaked when the first kid was born (159 +/- 6 beats min-1, P < or = 0.05), as did plasma adrenaline concentration (from 0.4 +/- 0.2 nmol L-1 to 2.7 +/- 1.2 nmol L-1, P < or = 0.05). The concentration of noradrenaline increased from 4.8 +/- 2.3 nmol L-1 to 12.2 +/- 8.4 nmol L-1 (P < or = 0.05), when the head of the first kid was visible. Expulsion of the second and third kids caused relatively smaller increases in blood pressure, heart rate and catecholamines than those seen with the first born kid. It is concluded that changes in pressure, heart rate and catecholamines during parturition are related to the different phases of labour and not to its duration or severity.

[Appendicitis in childhood]

From 1989 to 1995 high-resolution ultrasonography (US) was performed in 3,546 children (age: 1-17 years) with clinically suspected appendicitis. A total of 518 patients underwent laparotomy; 420 had histologically proven acute or perforated appendicitis (prevalence 11.8%). In these children, the sensitivity, specificity and overall accuracy of US examination were 90%, 97% and 96% respectively. The use of US in clinically doubtful acute abdomen may allow earlier diagnosis of acute appendicitis; in 1995 the rate of unnecessary appendectomy was reduced to 13%.

Genetic alteration of alpha 2C-adrenoceptor expression in mice: influence on locomotor, hypothermic, and neurochemical effects of dexmedetomidine, a subtype-nonselective alpha 2-adrenoceptor agonist

alpha 2-Adrenergic receptors (alpha 2-ARs) regulate many physiological functions and are targets for clinically important antihypertensive and anesthetic agents. Three human and mouse genes encoding alpha 2-AR subtypes (alpha 2A, alpha 2B, and alpha 2C) have been cloned. We investigated the involvement of the alpha 2C-AR in alpha 2-adrenergic pharmacology by applying molecular genetic techniques to alter the expression of alpha 2C-AR in mice. The effects of dexmedetomidine, a subtype-nonselective alpha 2-AR agonist, on monoamine turnover in brain and on locomotor activity were similar in mice with targeted inactivation of the alpha 2C-AR gene and in their controls, but the hypothermic effect of the alpha 2-AR agonist was significantly attenuated by the receptor gene inactivation. Correspondingly, another strain of transgenic mice with 3-fold overexpression of alpha 2C-AR in striatum and other brain regions expressing alpha 2C-AR showed normal reductions in brain monoamine metabolism and locomotor activity after dexmedetomidine, but their hypothermic response to the alpha 2C-AR agonists was significantly accentuated. The hypothermic effect of alpha 2-AR agonists thus seems to be mediated in part by alpha 2C-AR. Some small but statistically significant differences between the strains were also noted in brain dopamine metabolism. Lack of alpha 2C-AR expression was linked with reduced levels of homovanillic acid in brain, and mice with increased alpha 2C-AR expression had elevated concentrations of the dopamine metabolite compared with their controls.

Risk of physical assaults among student nurses

This study was undertaken within two teaching hospitals (one general and one psychiatric) in a large health board. Its purpose was to compare the rates of physical assaults on student nurses with those on other grades of nursing staff, to explore the aetiological factors associated with attack, and to identify what preventive measures were in place and what support systems were available for affected staff. Data were collected from completed incident forms and from a semi-structured questionnaire administered to the student nurses. The rate of reported assault was much higher in the psychiatric hospital than the general hospital, but the severity of the assault was greater in the general hospital. Age and height were not risk factors for assaults. The study showed inadequate training, under-reporting of incidents, poor utilization of occupational health departments and a lack of support for victims of physical assaults.

[Pelvic vein thrombosis in protein C deficiency after infectious mononucleosis]

Subsequent to an infectious mononucleosis a 15 year old girl developed a thrombosis of the iliaca vein. Laboratory evaluation revealed a heterozygous form of protein C deficiency. An infusion with r-tPA (= recombinant tissue plasminogen activator) at a rate of 0.02 mg/kg BW/h over 96 hours failed to reopen the vessel. After intermittent heparin therapy longterm treatment with coumarin began. Three months later the iliaca vein was partially recanalised.

Comparison of skin changes induced on mice by either group A type 12 or group G streptococci

Adult Swiss webster mice were injected with 3 x 10(6) colony-forming units (cfu) of group G or 2.5 x 10(6) cfu of group A streptococci at intradermal injection sites on the right and left paralumbar areas of the back. The mice were sacrificed at intervals between 4 hours and 14 days post-injection (p.i.) and full thickness biopsies of skin 10 mm in diameter encompassing the sites of injection were taken. One tissue specimen was homogenized in PBS and plated to determine the number of cfu, while another was used for histopathological studies. The number of viable group A and group G streptococci in the tissue increased to 3 x 10(9) cfu by 96 hours p.i.: after 192 hours p.i. the group A cells had declined to 2.7 x 10(6) cfu compared to 1.1 x 10(8) cfu for group G cells. No streptococci of either group were detected at 336 hours (14 days p.i.). Gross edematous lesions induced by either streptococcus group were evident on all animals at 24 hours (p.i.). Group G streptococci lesions were larger and persisted longer than lesions induced by group A. Histological examination consistently revealed more inflammation and necrosis in tissue sections from mice injected with group G streptococci.

Relationships between dietary ascorbic acid status and deficiency, weight gain and brain neurotransmitter levels in juvenile rainbow trout,Salmo gairdneri

A study was conducted to determine the interrelationships between dietary ascorbic acid (AA) concentrations, brain neurotransmitter levels and weight gain in juvenile rainbow trout. At the end of 4 weeks and until the end of 12 weeks of feeding test diets of varying AA concentrations (0-320 mg AA/kg diet), increased weight gain was noted in fish fed the AA-free diet. However, by the end of 13 weeks and until the end of the experiment this phenomenon was no longer evident; instead the fish showed the more classical deficiency signs of anorexia and decreased weight gain. After 12 and 24 weeks, there were no significant differences in brain serotonin (5-HT), 5-hydroxyindoleacetic acid (5-HIAA), norepinephrine (NE) or dopamine (DA) between fish reared on the different test diets. However, after 12 weeks of feeding the test diets, brain 5-HT, brain AA and weight gain were significantly correlated with one another. No such relationships were found for brain NE or brain DA. After 24 weeks of feeding the diets, the relationships between brain 5-HT, brain AA and weight gain were no longer apparent. Similarly, after 24 weeks brain NE and DA were also unrelated to brain AA and weight gain. These results provide evidence that in very young rainbow trout, AA deficiency, brain 5-HT levels and weight gain were related. However in fish reared on the diets for 24 weeks these relationships were no longer evident.